I think this has a lot of potential, and works as a proof of concept. As an animation project, I can only commend it. It does make me wonder about the details of some of the mechanics demonstrated. Water Jumping: Supposedly a matter of timing, that if just hit jump as you hit the water's surface, and perhaps if you have enough speed, you can bounce off it (probably a limited number of times?). Ledge Climbing: Easy to understand. Running Up Walls: You might be able to do this by holding "up" as you run into the wall. I really like this feature, as it gives you a lot of freedom to explore. Rock-Hopping: For this, I'd guess it to be a matter of not quite clearing the rock with your jump. If you clear it and jump well over it, no animation plays. If you hit the edge of it, the animation plays. As presented, it has the benefit of slowing down the game for a moment for you to regain your bearings--so long as you don't lose them all when you return to speed (which seems quite possible). At the moment, it is hard to think of it as much more than a cool aesthetic touch. However... we must consider the irritation involved with just barely clipping the top of an obstacle, and your run being stopped. Freedom in the concept's title does seem to imply the amount of freedom of movement, as well as being lenient towards mistakes. Powers: I noticed two powers in the trailer, the double jump and aimed attack. It's possible they have more possible powers in mind, and are considering the ability to choose a couple. Double Jump: To avoid accidentally activating this, it may be preferable to tap and hold the jump button to activate this, or even use a second button. This power has advantages in timing and in reaching higher places or getting a second chance at your jump. They also show Sonic being sucked to a certain launch point for the second jump, so I wonder about the intentions behind that. Besides the effect looking interesting, it may have some utility in preventing abuse. It could probably work with tap and hold. Then you have to hold the jump button for about 0.2 seconds before you stop in midair (then can hold remain there for up to 2 seconds or such). That would make it unlikely you would accidentally use this. This would also make it less useful/abusable for certain situations. At 5 rings a pop, a double jump has a lot of utility, so additional limitations may be necessary (I expect it can't be turned into a triple jump). Aimed Attack: I find it very interesting that instead of Sonic turning on the spot, he rotates in a way I currently don't understand (it looked like the controls orbited the enemy). This is another handy way of giving the player a moment to reconsider their actions, and gives them a flexible mode of travel at the reasonable price of 10 rings. Falling Rocks: Not sure this is the best timing on these. Someone replaying the stage could easily accomplish this, but someone new wouldn't have enough time to wall jump up them to Robotnik (which would be fun) and mightn't get the timing of their fall. You could fix that by changing the effects and giving a tell. Having the screen shake a bit during Robotnik's attack instead of dirt falling from across the ceiling. Then, have dirt fall right under where the rocks are about to fall from, just before they do fall. As it is, they seem to be going too fast to wall jump up them or use them as platforms. So slowing down their fall, or maybe having them slow down briefly before they sink into the ground, that's worth considering. Non-Spin Jump on Robotnik: This is really neat, but I have trouble thinking of how it would fit in. I love it when retro games don't have you get hurt the moment you touch the enemy (unless they're spikey or on fire), so being able to stand on Eggman is quite interesting. A few times in the video, Sonic jumps without spinning, then often assumed a spinball in midair. Some of it was contextual, like hopping over the rocks, or jumping off a "ramp" in the terrain over that river, but in this moment it's really hard to see why this happened. Looking at it again, it looks the same as hopping over those rocks, same animation, and it could use the same mechanics. Except, Sonic jumps without spin-balling. While you could have a hop mechanic, where just tapping the jump button results in such a hop, it doesn't sound practical for gameplay purposes and ruins your dynamic control of jump height. You could consider using two jump buttons, and a lot of the skill in the game would be knowing when to use which jump, and combining them. But, for most of what we've seen, I think you could manage with one jump button, so justifying a second one is hard. Alternatively, you could try something like holding "up" as you jump perform this preset hop. I recall that being used in some games. Useful for certain areas, where you want a specific jump arc, or where you don't want to spinball for some reason. It could also be given special utility. Maybe later there are some enemies you can grab onto, then jump off of, if you aren't spin-balling (a little like Ristar)? Still, this is questionable, unless you have a vision for this in the game. I do like the aesthetic, all the same. Somersault: That somerwault at the end, where he frees the animals. While that would probably be just an animation that would play out, you could consider adding the somersault to the game. Suddenly pressing "backwards" (the opposite of the direction you're moving) then jumping may result in this jump. That, however, has the potentially of happening when you don't mean it to. It might work if you have to press, "Jump+Backwards+Up" or such. Or if you did add a second jump button in, it wouldn't be hard to implement. As for utility? It's a good way to get some decent jump height, and/or come to a stop. Still, that makes it questionably valuable. Enemy and Environment Designs: Not sure I like this art style for the enemies, save Robotnik who looks fine. The environment is fine, or OK, to me for this jungle level. Looks better than Sonic 4, to me.... But still, yeah, more colours and a more interesting environment like in the OVA would be appreciable.